Two selective media, malachite green-bacitracin (MGB) agar and tryptic soy-serum-bacitracin-vancomycin (TSBV) agar, were compared for the isolation of Actinobacillus actinomycetemcomitans. The highest recovery was found on TSBV agar plates cultured in air-5% CO2 both for plaque samples from periodontal pockets and for pure cultures.